Guy I work with that used to be a welder by trade reckons that for extending tubular stuff the slug/sleeve is redundant and that just welding the 2 bits together is strong enough.
It was handlebars I was asking him bout and given that I was using a shitty stick welder and am a shit welder he did say the slug probably wasn't a bad idea as it'd hold everything straight and allow me to burn the weld in a bit harder.
Guy I work with that used to be a welder by trade reckons that for extending tubular stuff the slug/sleeve is redundant and that just welding the 2 bits together is strong enough.
It was handlebars I was asking him bout and given that I was using a shitty stick welder and am a shit welder he did say the slug probably wasn't a bad idea as it'd hold everything straight and allow me to burn the weld in a bit harder.